1. Field of the Invention
The present invention relates to a filter system for filtering a fluid such as liquid or gas.
2. Prior Art
In cleaning the electronic components, precision fabrication parts, etc., cleaning solultion is filtered through a filter to improve degree or quality of cleaning. A filter system of this type generally comprises a filter element for filtering a fluid, a filter case in cylindrical shape with its upper end opened to accommodate the filter element, and a filter cover to close the upper end of the filter case, whereby the filter cover is provided with an inlet and an outlet for the fluid so that the fluid entering through the inlet is filtered while it passes through the filter element and is discharged through the outlet. The filter cover is fixed at an adequate position, and in case the filter element is to be replaced, the filter case is inserted into or removed from the filter cover.
However, in the conventional type filter system as described above, the filter cover and the filter case are fixed on each other by nut means, and the filter case must be inserted or removed using a tool such as spanners. Thus, insertion and removal of the filter case are considerably difficult to perform and are almost impossible to achieve by a single person. As a result, two workers are required, i.e. a worker to support the filter case and a worker to tighten and loosen the nut means using a tool. Moreover, because the filter element is pressed against the filter cover by means of a spring provided on inner bottom of the filter case, the filter case with considerable weight must be pressed against the filter cover by resisting spring force when the filter case is to be mounted. This requires application of substantial force and the worker must make strenuous efforts and may feel tired on hands.
There is also another type of filter system, in which the filter cover and the filter case are fixed on each other by fastening means such as a band. This is superior to the nut type system in that there is no need to tighten or loosen the nut using tool. However, it is as disadvantageous as the nut type system in that the weighty filter case must be pressed on the filter cover against the force of the spring.
In this connection, there are strong demands on the development of a filter system, in which the filter cover and the filter case can be easily inserted or removed.